The invention relates generally to power-driven conveyors and more particularly to articulated modular plastic conveyor belts.
Modular plastic conveyor belts enjoy wide application in the food-handling industry. Modular plastic belts are constructed of a series of rows of plastic belt modules linked together at hinge joints between consecutive rows. Hinge eyes at the leading and trailing ends of each row are interleaved with the hinge eyes of leading and trailing belt rows. A hinge pin extends through a passageway formed by the interleaved hinge eyes to form the hinge joints at which the belt can articulate about drive and idle sprockets. Unlike flat belts, which are pre-tensioned and frictionally driven by pulleys, modular plastic belts are not pre-tensioned and are positively driven by toothed drive sprockets. Modular plastic belts have drive structure, e.g., drive bars and drive pockets, engaged by drive faces or sprocket or drum teeth.
When a modular plastic conveyor belt is used in a food-contact application, for example, grease and other contaminants that build up must be periodically cleaned from the belt. Belts with a lot of nooks and crannies, which are hard to access with a water spray, are difficult to clean. The drive structure in belts, a recessed drive pocket, for example, is difficult to clean.
Modular plastic flat-top conveyor belts are often used on butchering lines. The flat top of the belt provides a cutting surface for butchering operations. The cutting surface is naturally subject to abrading and scoring by bones and butcher knives and cleavers. And the belt must be able to absorb the impacts of knives and cleavers as well as the impacts of heavy carcasses dropped onto the cutting surface. Many modular plastic meat belts have a transverse drive bar between the hinge eyes, and impacts on the cutting surface are transmitted through only the drive bar and the hinge eyes.